1. Field of the invention
The present invention relates to a body motion display device and a body motion display method which display body motion of a subject at the time of photographing of a radiographic image.
2. Description of the Related Art
When photographing a subject by irradiating the subject with radiation, such as X-rays, to photograph the subject and acquiring a radiographic image of the subject, the acquired radiographic image may be blurred due to body motion caused by movement of the subject during photographing, and image quality may be deteriorated. In particular, when a photographing target is a region where the irradiation time of radiation is long, such as a neck, chest, abdomen, and waist, or when an infant is photographed, body motion is likely to occur, and thus, deterioration of the radiographic image becomes a problem.
A technician who performs photographing observes the condition of a subject during photographing and immediately confirms an acquired radiographic image, whereby the presence or absence of body motion can be determined. Meanwhile, a monitor in a photographing room has low resolution and displays a radiographic image on a reduced scale, and in many cases, an observation environment is comparatively bright. For this reason, it is difficult to determine the presence or absence of body motion by observing a displayed radiographic image. In this case, the presence or absence of body motion is determined by magnifying a radiographic image and confirming body motion of the entire radiographic image while moving the magnified region on the radiographic image. However, this operation degrades the workflow of the radiology technician who performs photographing.
For this reason, a method which automatically detects body motion based on a radiographic image and displays a detection result has been suggested. For example, a method has been suggested, in which deterioration of an edge in a radiographic image is learned as feature quantities in two directions of a vertical direction and a horizontal direction, a plurality of regions of interest are set on the radiographic image, an edge is extracted from each region of interest, a probability that body motion is included in the region of interest based on the learned feature quantities and the extracted edge is calculated, and it is determined whether or not a shift due to body motion occurs in the radiographic image based on the calculated probability for each region of interest (see U.S. Pat. No. 7,899,229B). According to the method described in U.S. Pat. No. 7,899,229B, the radiographic image and the frame of a region of interest are displayed in a superimposed manner, and a region of interest where body motion is included is indicated with a different color from other regions of interest, or the like, whereby the presence or absence of body motion is easily recognized. A numerical value representing the probability that body motion is included in the region of interest is additionally displayed. Furthermore, a selected region of interest is displayed next to the radiographic image on a magnified scale, whereby body motion is easily confirmed.
A method has also been suggested, in which the presence or absence of body motion is automatically determined, and when body motion is present, a radiographic image is displayed on a magnified scale by an instruction of a technician (see JP2006-000376A).